Devices which are able to read, classify and determine the final destination of various documents, as for example check readers of mailing pieces scanners, are known in the art.
Examples of the prior art include U.S. Pat. No. 4,626,872 to Sapitowicz which shows a document scanner with interstage stops; and U.S. Pat. No. 4,796,242 to Pierce which shows a document scanner in which reading is performed on a cart. In this case, reading cannot be done at high speed and documents of different size or weight cannot be processed without modification of the machine.
U.S. Pat. No. 4,511,793 shows a machine which contains rollers in its transport mechanism and it includes the concept of change of direction but transport is slow and the rollers are not useful for document reading.
U.S. Pat. No. 4,798,944 to Corner, covers a machine capable of transversal movements which makes documents run in two different and separate ways, but which does not allow for high speed constant reading of equal quality.
U.S. Pat. No. 4,764,976 to Kallin, deals with a unit having as its basic property its ability to align the document to be read; a capacity which is not sought in the case of the present invention.
These known devices, apt for document classification, usually have complex transport mechanisms, are difficult to reach when a document is locked inside and their reading capacity does not reach high speed and versatility when facing a change in width, size or alignment of the document. For the sake of a correct understanding of the words used in the present paper, the key words are hereto defined.
Reading machine: a device capable of passing over a document through a reading station, performing the reading of that document-especially if it is of the bar code type-, assessing the information read and transmitting a determined command according to the reading performance.
Document: for the purpose of the present invention, a document is a laminar piece, preferably a cellulose one, with a printed code to be read by the machine.
Reading medium: the element by means of which the information contained in the document is retrieved when the document passes through the area influenced by that element; in the case of the present invention, the element is an optical scanner reading bar codes.
Bar code: a bar code is a series of parallel marks (or bars) grouped in a certain way so as to define a language which can be retrieved by means of the adequate reading media.
Travel mechanism (inside the machine): the circuit described by the document in the machine from the moment it is fed into it, to the moment it is ejected after reading and storage.
Feeding run-over: the section of the travel mechanism in which reading of a document is performed.
Traction wheels: the wheels which drive the document along the different stages of the travel mechanism.